1. Field of Invention
The present invention relates to a light source module, and specifically to a light-emitting diode (LED) integrated packaging light source module with a low color temperature and a high color rendering property.
2. Description of Related Arts
An LED, with the advantages such as a long lifetime, low power consumption, and being easily driven, has been widely applied in the production and daily lives of people's. In a currently used white-light LED, a blue light LED chip is usually used as an excitation light source to excite a YAG fluorescent powder to obtain yellow light, and the yellow light is then mixed with the rest blue light emitted by the blue light LED chip to obtain a demanded white light. The white light obtained by adopting such a “blue light LED+YAG fluorescent powder ”method has high luminous efficacy and a high color rendering property in the case of a high color temperature; however, in the case of a low color temperature, the color rendering index and the luminous efficacy are low, which can hardly meet the requirement of common lighting.
To solve the foregoing problem, a red fluorescent powder is usually added in a yellow fluorescent powder (for example, Patents CN1677695A, CN101414604A, and CN101195742A) to increase the red component in a white-light LED, so as to provide a color rendering index; however, the loss of luminous flux is high in adopting this method, making it unsuitable for practical applications. In another method, a white-light LED and a red-light LED are packaged in one same LED (for example, Patent CN1937222A), and the red light emitted by the red-light LED chip is used to alleviate the disadvantage that the white light lacks red light radiation. However, as AlGaInP system materials are adopted in a current red-light LED chip, the temperature resistance is low, and when the packaging is done near a blue light LED chip, the materials are susceptible to the heat generated by the blue light LED chip, which further affects the stability of the entire packaging module.